Introduce EventListener.Spec.ServiceType

Allows to set the type of the underlying eventlistener service.
If not set k8s will configure the service type to ClusterIP.

Depending on the cloud provider or the ingress controller used
the user might need to set the service type to `NodePort` or
`LoadBalancer` to expose it externally.

docs/eventlisteners.md

@@ -1,4 +1,5 @@
 # EventListener
+
 `EventListener`s connect `TriggerBinding`s to `TriggerTemplate`s and provide an
 addressable endpoint, which is where webhooks/events are directed.
 
@@ -9,16 +10,20 @@ with.
 When an `EventListener` is successfully created, a service is created that
 references a listener pod. This listener pod accepts the incoming events and
 does what has been specified in the corresponding
-`TriggerBinding`s/`TriggerTemplate`s. The service created is a `ClusterIP` service 
-which means any other pods running in the same Kubernetes cluster can access it via the service's 
-cluster DNS. For external services to connect to your cluster (e.g. GitHub 
-sending webhooks), check out the guide on [exposing eventlisteners](./exposing-eventlisteners.md) 
+`TriggerBinding`s/`TriggerTemplate`s. The service created is a `ClusterIP` service
+which means any other pods running in the same Kubernetes cluster can access it via the service's
+cluster DNS. For external services to connect to your cluster (e.g. GitHub
+sending webhooks), check out the guide on [exposing eventlisteners](./exposing-eventlisteners.md)
 
 ## Parameters
+
 `EventListener`s can provide `params` which are merged with the `TriggerBinding`
 `params` and passed to the `TriggerTemplate`. Each parameter has a `name` and a
 `value`.
 
+`EventListener` `spec.serviceType` can be set to `ClusterIP (default)` | `NodePort` | `LoadBalancer`
+to configure the underlying `Service` resource to make it reachable externally.
+
 ## Event Interceptors
 
 Triggers within an `EventListener` can optionally specify an interceptor field

pkg/apis/triggers/v1alpha1/event_listener_types.go

@@ -54,6 +54,7 @@ type EventListener struct {
 type EventListenerSpec struct {
 	ServiceAccountName string                 `json:"serviceAccountName"`
 	Triggers           []EventListenerTrigger `json:"triggers"`
+	ServiceType        corev1.ServiceType     `json:"serviceType,omitempty"`
 }
 
 // EventListenerTrigger represents a connection between TriggerBinding, Params,

pkg/reconciler/v1alpha1/eventlistener/eventlistener.go

@@ -154,8 +154,7 @@ func (c *Reconciler) reconcileService(el *v1alpha1.EventListener) error {
 		ObjectMeta: generateObjectMeta(el),
 		Spec: corev1.ServiceSpec{
 			Selector: mergeLabels(el.Labels, GenerateResourceLabels(el.Name)),
-			// Cannot be changed
-			Type: corev1.ServiceTypeClusterIP,
+			Type:     el.Spec.ServiceType,
 			Ports: []corev1.ServicePort{
 				servicePort,
 			},
@@ -170,6 +169,13 @@ func (c *Reconciler) reconcileService(el *v1alpha1.EventListener) error {
 			existingService.Spec.Selector = service.Spec.Selector
 			updated = true
 		}
+		if existingService.Spec.Type != service.Spec.Type {
+			existingService.Spec.Type = service.Spec.Type
+			// When transitioning from NodePort or LoadBalancer to ClusterIP
+			// we need to remove NodePort from Ports
+			existingService.Spec.Ports = service.Spec.Ports
+			updated = true
+		}
 		if !cmp.Equal(existingService.Spec.Ports, service.Spec.Ports, cmpopts.IgnoreFields(corev1.ServicePort{}, "NodePort")) {
 			existingService.Spec.Ports = service.Spec.Ports
 			updated = true

pkg/reconciler/v1alpha1/eventlistener/eventlistener_test.go

@@ -130,7 +130,7 @@ func Test_reconcileService(t *testing.T) {
 		ObjectMeta: generateObjectMeta(eventListener0),
 		Spec: corev1.ServiceSpec{
 			Selector: generatedLabels,
-			Type:     corev1.ServiceTypeClusterIP,
+			Type:     eventListener1.Spec.ServiceType,
 			Ports: []corev1.ServicePort{
 				servicePort,
 			},
@@ -457,9 +457,12 @@ func TestReconcile(t *testing.T) {
 	eventListener2 := eventListener1.DeepCopy()
 	eventListener2.Labels = updateLabel
 
-	eventListener3 := eventListener1.DeepCopy()
+	eventListener3 := eventListener2.DeepCopy()
 	eventListener3.Spec.ServiceAccountName = updatedSa
 
+	eventListener4 := eventListener3.DeepCopy()
+	eventListener4.Spec.ServiceType = corev1.ServiceTypeNodePort
+
 	var replicas int32 = 1
 	deployment1 := &appsv1.Deployment{
 		ObjectMeta: generateObjectMeta(eventListener0),
@@ -507,14 +510,14 @@ func TestReconcile(t *testing.T) {
 	deployment2.Spec.Selector.MatchLabels = mergeLabels(updateLabel, generatedLabels)
 	deployment2.Spec.Template.Labels = mergeLabels(updateLabel, generatedLabels)
 
-	deployment3 := deployment1.DeepCopy()
+	deployment3 := deployment2.DeepCopy()
 	deployment3.Spec.Template.Spec.ServiceAccountName = updatedSa
 
 	service1 := &corev1.Service{
 		ObjectMeta: generateObjectMeta(eventListener0),
 		Spec: corev1.ServiceSpec{
 			Selector: generatedLabels,
-			Type:     corev1.ServiceTypeClusterIP,
+			Type:     eventListener1.Spec.ServiceType,
 			Ports: []corev1.ServicePort{
 				servicePort,
 			},
@@ -525,6 +528,9 @@ func TestReconcile(t *testing.T) {
 	service2.Labels = mergeLabels(updateLabel, generatedLabels)
 	service2.Spec.Selector = mergeLabels(updateLabel, generatedLabels)
 
+	service3 := service2.DeepCopy()
+	service3.Spec.Type = corev1.ServiceTypeNodePort
+
 	tests := []struct {
 		name           string
 		key            string
@@ -567,14 +573,30 @@ func TestReconcile(t *testing.T) {
 			startResources: test.TestResources{
 				Namespaces:     []*corev1.Namespace{namespaceResource},
 				EventListeners: []*v1alpha1.EventListener{eventListener3},
-				Deployments:    []*appsv1.Deployment{deployment1},
-				Services:       []*corev1.Service{service1},
+				Deployments:    []*appsv1.Deployment{deployment2},
+				Services:       []*corev1.Service{service2},
 			},
 			endResources: test.TestResources{
 				Namespaces:     []*corev1.Namespace{namespaceResource},
 				EventListeners: []*v1alpha1.EventListener{eventListener3},
 				Deployments:    []*appsv1.Deployment{deployment3},
-				Services:       []*corev1.Service{service1},
+				Services:       []*corev1.Service{service2},
+			},
+		},
+		{
+			name: "update-eventlistener-servicetype",
+			key:  reconcileKey,
+			startResources: test.TestResources{
+				Namespaces:     []*corev1.Namespace{namespaceResource},
+				EventListeners: []*v1alpha1.EventListener{eventListener4},
+				Deployments:    []*appsv1.Deployment{deployment3},
+				Services:       []*corev1.Service{service2},
+			},
+			endResources: test.TestResources{
+				Namespaces:     []*corev1.Namespace{namespaceResource},
+				EventListeners: []*v1alpha1.EventListener{eventListener4},
+				Deployments:    []*appsv1.Deployment{deployment3},
+				Services:       []*corev1.Service{service3},
 			},
 		},
 		{